Circuit testers for testing electronic devices or systems are well-known in the art and are typically used to test one or more operational states of such electronic devices or systems. For example, a circuit tester may be used to test an electronic system after fabrication but before final assembly to ensure that the various circuits and devices comprising the system function properly. Alternatively, other test scenarios are also used.
Generally speaking, circuit testers operate by electrically connecting to various circuit nodes of the electronic system. For example, in one testing procedure, electronic signals are detected or probed by the circuit tester. The detected signals are then analyzed by an analyzer associated with the circuit tester. In another type of testing procedure, the circuit analyzer may generate an electronic signal that is then “injected” into the appropriate circuit node. The response of the device may then be analyzed.
Regardless of the particular testing procedure that may be used by the circuit tester, some means must be provided to electrically connect the circuit tester to the device to be tested. In perhaps the most simple embodiment, one or more elongate, needle-like test probes are positioned by hand to contact the appropriate circuit nodes. More commonly, however, the probing apparatus tends to be considerably more complex, such as the so-called “bed-of-nails” probes that are commonly used to simultaneously probe tens, or even hundreds, of circuit nodes on a printed circuit board.
However, the increasing complexities of electronic systems are placing ever-increasing demands on test probe apparatus, from both mechanical and electrical standpoints. For example, it is not uncommon for current electronic systems to include one or more large scale integrated circuits having a very large number (e.g., hundreds) of contact points or nodes. While it may not be necessary to probe each and every contact point or circuit node, the mere fact that the nodes are increasing typically means an increase in the number of nodes that must be probed in order to effectively test the electronic system. In addition, the increasing clock speeds of digital systems means that the probing of the signals produced by such systems must be accomplished with as little mechanical and electrical impact as possible in order to ensure that the probing process itself does not adversely affect the operation of the system.